The present invention is directed to a three-winding hermetic induction motor which is connected to a single-phase power supply. Traditionally, both single-phase and three-phase hermetic motors are connected by only three electrical conducting terminals to the electrical circuits external to the hermetic enclosure. For our unique connection of the six winding terminals of a three-winding motor to a single-phase supply using the Semi-Hex circuit, four conductors are provided and used in the hermetic bushing in the wall of the enclosure.
A Semi-Hexagon electrical motor circuit is disclosed in U.S. Pat. No. 5,300,870, issued Apr. 5, 1994, titled “Three-Phase Motor Control”, to Otto J. M. Smith. In FIG. 1 of this patent, three motor windings are shown in the Semi-Hexagon (Semi-Hex) winding configuration and connection. This reference is hereby incorporated by reference.
The publication “High-Efficiency Single-Phase Motor”, by Otto J. M. Smith was published in the IEEE Transactions on Energy Conversion, Vol. 7, No. 3, September 1992, ITCNE4 (ISSN 0885-8969) Pages 560-569. FIG. 2, page 561 is an illustration of an exemplary Semi-Hexagon circuit. This reference is hereby incorporated by reference.
The publication “High-Efficiency Single-Phase Motor”, by Otto J. M. Smith, published in the Power Engineering Review, No. 9, Vol. 12, pages 47-48, September, 1992. (ISSN 0272-1724) provides a review of 91 SM 392-1 EC, T-EC September 1992. FIG. 1 on page 47 of this publication shows an illustration of an exemplary Semi-Hexagon circuit. This reference is hereby incorporated by reference.